Alvania erecta

Alvania erecta is an extinct species of minute sea snail, a marine gastropod mollusc or micromollusk in the family Rissoidae.

Description
The length of the shell is 2 mm, and its diameter is 1 mm.

(Original description) The minute shell is ovate-conical. It contains 6 convex whorls. The body whorl is rather tumid and much the largest. The shell is ornamented by numerous fine longitudinal ribs which die out at the periphery, and by delicate spiral lines which become somewhat stronger below it. The suture is distinct and slightly channelled, with a spiral line immediately above it. The spire is short, regularly diminishing in size towards an acute point. The oval aperture is rather small. The outer lip is gently rounded, incurved above and not much expanded. The inner lip is somewhat reflected. The peristome is continuous.

Distribution
Fossils of this species were found in late Pliocene strata at St. Erth, Cornwall, Great Britain.